The specificity of the Spodoptera frugiperda digestive beta-glycosidase (Sfbetagly50) for fucosides, glucosides and galactosides is determined by noncovalent interactions of glycone 6-OH and glycone 4-OH with the active-site residues Q39 and E451. Site-directed mutagenesis and enzyme steady-state kinetics were described, showing that replacement of E451 with glutamine increased the preference of Sfbetagly50 for glucosides in comparison to galactosides, whereas replacing E451 with serine had the… CONTINUE READING